Cirton

The citron is a fragrant citrus fruit, botanically classified as Citrus medica by both the Swingle and Tanaka systems. The designation medica given it by Linnaeus is apparently derived from its ancient name "Median or Persian apple" that was reported by Theophrastus, who believed it to be native to Persia or the land of the Medes; there is no relation to medicinal uses of the fruit.

In Iran, the citron's thick white rind is used to make jam

It is thought that by the time of Theophrastus, the citron was mostly cultivated in the Persian Gulf on its way to the Mediterranean basin, where it was cultivated during the later centuries in different areas as described by Erich Isaac.